what is this...

[Obin Olson]

Wondering what this is..look at the weird motion blur on the edges...

 

[Adrian T.]

Could be a flickering lamp. It flickered three times during the exposure of this frame.

 

[Obin Olson]

hmm I hope so and not artifacts of the sensor motion blur...

 

[Álex Montoya]

Looks like frame blending by having chosen a wrong frame rate in your editing program.

 

[NateWeaver]

Yeah, either frame blending, or most likely the cycling of the streetlamps.

Sources that do flicker but do not show up in regular footage can do this when there's motion involved.

 

[AmariahOlson]

not frame blending that is out of redcine

 

[Dj Joofa]

Wondering what this is..look at the weird motion blur on the edges...

Seems like ghosting effect to me. If temporal filtering is too harsh it can also cause ghosting effects.

 

[Obin Olson]

whatever it is...it's in all the night time footage tests...23.98fps 1/48 shutter 2:1 4k

and I don't much care for it....

 

[jbeale]

Could be a flickering lamp. It flickered three times during the exposure of this frame.

If you have 120 Hz flicker on your lamp (both cycles of 60 Hz power) and your shutter is around 1/40 sec that gives you three full cycles, which would give you the triple-exposure look on fast motion. Exact same thing would happen with a DSLR, film camera, progressive-scan video camera, or any other camera with a 1/40 sec shutter exposure.

As Joofa mentioned, similar things happen with temporal filtering, if you're doing that.

 

[Obin Olson]

test footage

test footage

Here is the first part of this test seq shot at night with no lighting other then the sodium vapor lights...

www.dv3productions.com/RED/running_seq.mov

 

[Obin Olson]

this is not an artifact of frame blending...gotta be the lights...thx for info

 

[jbeale]

Here's a quick test: go out at night under that same sodium vapor light, and hold up one hand palm out with the fingers spread apart, and rock your hand quickly from side to side. How do the fingers look? I'm guessing you may see the same stroboscopic effect with your eye. If so, then it's "real" and any camera will show you a similar problem- I think the only way to avoid that is not have fast action, or replace the light with a less flickery one.

 

[Nick Gardner]

well what frame rate and shutter were you shooting at?

 

[Nick Gardner]

and whats up with the magic back pack ;-)

 

[Harry Clark]

I would vote for a flickering light as well...
Cheers,
Harry

 

[AmariahOlson]

if it is flickering light that would mean all lights in the BG far off distance are also flickering...(look at the last shot in the sequence).. you will notice they also have the 3 step motion blur. I think we are just going to have to do a test tonight with a tungsten light using 1/48th second shutter and see if this artifact exists or not.

 

[Harry Clark]

Indeed they are... but somewhat covered by motion blur and bokeh.
See attached frame.
Cheers,
Harry

 

[Obin Olson]

it's a magic backpack. you nailed it.

 

[Andrew Walker]

Footage looks kind of interesting. It is the lights. I get the same thing when I move my DSLR around with the shutter open on some MV lights. You can see in the line of light the it makes a pulse of light. I'm sure there's a shutter speed that might lessen the effect.

 

[Policar]

I got the same thing using an HVX with an hmi. It's normal.